Semi-automatic Telegraph Key

Description (Brief)
Semi-automatic keys like this one automatically produced rapid morse code dots by using a weighted pendulum to quickly make and break contact in the electrical circuit. The operator would make the dashes manually but could send much faster than with an ordinary key.
Electric Specialty Manufacturing Company produced this key under license from a company that worked with Horace Martin, inventor of "Vibroplex" semi-automatic key.
Currently not on view
Object Name
sending key
telegraph key
Electric Specialty Manufacturing Company
Physical Description
steel (overall material)
plastic (overall material)
cloth (overall material)
rubber (overall material)
copper (overall material)
overall: 10 cm x 23 cm x 7.5 cm; 3 15/16 in x 9 1/16 in x 2 15/16 in
ID Number
accession number
catalog number
Telegraph Keys
See more items in
Work and Industry: Electricity
Telegraph Keys
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
from Mr. and Mrs. Dan Hobaugh
Additional Media

Visitor Comments

Add a comment about this object

Submit a comment or ask a question about this object using the form below. Submissions are moderated and may receive a curator response. Please note that we cannot evaluate or appraise your personal artifacts. For other questions or general inquiries please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.